1. (Technical Field)
The present invention relates to a power conversion apparatus in which a semiconductor module and a cooler, which cools the semiconductor module, are held by a frame.
2. (Related Art)
One example of power conversion apparatuses has a semiconductor module which includes switching elements and a cooler which cools the switching elements. In addition, when holding the cooler by a frame, which holds the switching elements and the cooler inside thereof, a clamp may be used to fix the cooler to the frame. That is, the cooler can be fixed to the frame by fixing a cylindrical pipe, which introduces or discharges a cooling medium stored in the cooler, to the frame by the clamp.
As disclosed in JP-UM-A-56-125511, the clamp generally has a pressing portion which has an arched shape along the outline of the cylindrical pipe. Meanwhile, a fastener portion fastening the clamp to the frame has a flat plate shape.
Hence, an inner projecting portion, which projects to the side of the cylindrical pipe, is formed at the boundary between the fastener portion and the pressing portion (refer to the comparative example and FIG. 12 described later).
However, when the inner projecting portion is formed on the clamp, the inner projecting portion may dig into the cylindrical pipe depending on the arrangement by which the clamp holds the cylindrical pipe. This can locally crush the cylindrical pipe.
In addition, when the clamp is in a state where the curved surface of the arched pressing portion of the clamp contacts the curved outer periphery surface of the cylindrical pipe, pressure from the clamp cannot be linearly applied to the frame. That is, when the contact surface between the clamp and the cylindrical pipe has an arched shape, it is difficult to keep the direction in which the pressure is applied constant. The pressure can be applied in the direction diagonal to the direction in which the pressure is applied to the frame. In this case, the pressure may be applied in the direction in which the cylindrical pipe would detach from is the frame. This can make it difficult to steadily fix the cylindrical pipe.